Improvement in burglar-alarms



C. O. DUSBNBURY.

Burglar-Alarm.

No. 196,975. Patented Nov. 13,1877.

UNITED STATES PATENT EEICE,

O. 4GOLES DUSENBURY, OF NEW YORK, N. Y.

IMPROVEMENT IN BURGLAR-ALARMS.

Specification forming part of Letters Patent No. 196,975, dated November13, 18.77 application iiled October 12,1877.

To all whom it may concern t Be it known that l, O. GoLEs DUsENEURv', ofNewYork city, county of New York, and State of New York, have inventedcertain new and useful improvements in a device for operatingburglar-alarms, either in forms of clocks or in form of othercontrivances, by aid of which an alarm or noise .may be created and I doherebydeclare that the following is an exact and true description yof myinvention, which will enable others to make and use the same, referencebeing had to the accompanying drawing, forming a part of thisspecification, and to the letters and figures of reference markedthereon.

The object of my invention is to provide means for preventing any personentering a room through the `door without creating a noise, by which theoccupant of the room is warned of the intruder. The device I employ isso simple, so portable and inexpensive that it cannot fail to proveinvaluable, especially to travelers sleeping in hotels or inns.

My invention consists in providing an attachment to the door-knob or thedoor-knob axle of a lock, and which may readily be attached or detachedat will. When attached it will turn with the door-knob and cause aweight loosely hung to the outer extremity of the same to drop down, bywhich the trigger view of a door and door-frame embodying my invention.Fig. II is a detached plan view of the attachment.

A is the door-frame, to which is attached the alarm B with the triggerb. C is the door with the door'knob D. E is the door-knob or door-knobaxle attachment, consisting of a piece of wire, bent, as shown in lFig.II, in such a manner that the semicircular-formed end f will encirclethe door-knob or axle, as shown in Fig. I, and which is accomplished bypressing together the arms g and h, and fastening the hook p on arm g tothe end of arm h, On the top of the center part of arm g is hung theweight W, which is connected by string S to the trigger b.

It will be readily be understood that when the door-knob D is turned theattachment E will also turn, and cause the weight W to drop down fromthe same, and thus cause the alarm to be sounded.

Having thus described' my invention, I de sire to claim- A device foroperating an alarm-clock or similar contrivance by the turning of thedoorknob, consisting of the semicircular end f, the arm g, with hook p,and arm h, in combination with cord S and weight W, substantially asdescribed, and for the purpose set forth.

O. GOLES DUSENBURY. Witnesses:

F. BARRITT, GHR. RLEGELMAN.

